Demonstration of the HiPOx Advanced Oxidation Technology for the Treatment of MTBE-Contaminated Groundwater
The HiPOx technology is an advanced oxidation process that incorporates high-precision delivery of ozone and hydrogen peroxide to chemically destroy organic contaminants with the promise of minimizing bromate formation. A MTBE-contaminated groundwater from the Ventura County Naval Base in Port Hueneme, CA was used to evaluate this technology. Due to extremely high concentrations of bromide in the feed water (1.3 mg/L) and the desire to limit bromate formation, an experimental system was operated with 630 ozone injector ports in series. In all trials, the HiPOx system reduced MTBE from 748 :g/L to below its regulatory limit of 5 :g/L; however, bromate was not maintained below its regulatory limit of 10 :g/L. The oxidative intermediate tert-butyl alcohol (TBA) was below its regulatory effluent limit of 12 :g/L in two of the three trials. Both MTBE and bromate were under their regulatory limits at intermediate sampling ports that corresponded to 330, 470, and 540 injector ports for the three runs. However, TBA was above its regulatory limit at these locations for all three runs. To control TBA, more injection ports were required. However, as shown above, additional injection ports increased the bromate concentration above its regulatory limit. Therefore, the experimental HiPOx system was not fully successful with this atypical water at the chosen oxidant doses. A model calculation is presented that uses many simplifying assumptions to show that this HiPOx system may have been fully successful at this location under the chosen oxidant doses if the influent bromide concentration was 0.56 mg/L, or less. Since a bromide concentration of 0.56 mg/L is still extremely high for a drinking water source, the HiPOx system appears to hold promise for destroying MTBE and its oxidative byproduct TBA while controlling bromate formation, even in waters that have high bromide concentrations. However, before application to other sites, pilot testing will be needed due to the uncertainty in performance resulting from source-water quality differences. Appendix A contain the manufacturer’s supporting data from other sites and data collected by the manufacturer during the demonstration runs described herein.